Now a days, flickering in LED is a challenge for researchers as it has adverse effect on human health. Using electrolytic capacitor was the initial solution for flickering. However, electrolytic capacitors are not preferred for LED driver owing to short lifetime and more prone to fault. There exists several ripple cancellation (RC) techniques discussed in literature. However, they suffer from complex control structures and high stress across the switches. In this regard, this paper proposes a novel series current RC method to eliminate the double line low frequency ripple and also have removed the electrolytic capacitor. The key features of the proposed RC method include UPF operation throughout without any external circuitry by using the multilevel converter, simple control and reduced smoothing capacitance value. The validation of the proposed method in simulation has been presented.

A Decoupled Low-Frequency Ripple Cancellation Method for High-Power LED Driver circuits

This paper proposes an isolated flyback switch mode power supply (SMPS) light-emitting diode (LED) driver for lighting application. The LED driver features a single-stage AC/DC converter with minimal number of components which help to cut its cost. The LED driver is using a single switching transistor, without supplementary inductors, correctional circuitry, or clamping action, thus ensuring a low cost design. The SPICE modelled LED driver uses auxiliary voltage output to maintain the equilibrium of the system based on the feedback from the output. Simulation models report up to 95.44% efficiency.

A flyback SMPS LED driver for lighting application

In the paper, the electrical and optical parameters of wirelessly controlled LED lamps of the Hue type are analysed. Features of this class of wirelessly controlled LED lamps given by the producer are described and a measuring setup for the electrical and optical parameters of the considered LED lamps is proposed. The results of measurements of the two investigated lamps with variable hue, based on RGB chips or emitted white light of different CCTs (correlated colour temperatures), are shown and discussed. Attention was given to the parameters characterising the influence of the tested LED lamp on such electric power quality indicators as PF (power factor) and THD (total harmonic distortion). Therefore, the influence of voltage supply and the selected value of power density of the emitted light on the THD and PF is analysed and discussed.

https://www.mdpi.com/1996-1073/14/6/1612/pdf

Investigations of Electrical and Optical Parameters of Some LED Luminaires—A Study Case

This paper presented a comparative study in function reliability between dc-dc converters used in power LED. Between dc-dc converters more used to power LED are the Buck and Flyback converter, because the Buck provides a lower output voltage than the input, and in the case of flyback has galvanic isolation. The study has objetive to determine the reliability obtaining the failure rate of the system and the average time when failures occurs, because the LED driver must have an average life similar to the LED lamp. The reliability analysis is based in the standard MIL-HDBK-217, for this study performed was used a LED load of 54.6 W in both converters. The results have shown that the buck converter has a lower failure rate and a higher mean time between failures, therefore has a longer useful life.

http://ieeexplore.ieee.org/iel7/7389728/7395064/07395107.pdf

Comparative analysis of the reliability of drivers for power LED

Currently LED technology for lighting has a great boom in the automotive industry. In this industry it is required that the main headlights change luminosity instantaneously; this is achieved using LED arrays. In this type of power LED arrays can be controlled independently using a dc-dc converter for each of the arrays, or using a converter that controls the voltage or series depending on the change in brightness. An important factor in determining what type of strategy to implement is the failure rate of the system, as it is known that the greater the number of components or stages, the system will be more likely to fail in a certain time. In this article we analyzed the conditions of the Flyback converter for five power levels, it was established that the element with the highest failure rates is the switching MOSFET, this element was also the one that increased its temperature more in the last power interval. Therefore the study of this case determines that to have a lower failure rate it is recommended to have several converters of less power than a larger one.

Reliability Analisys of a Flyback Converter for Automotive Applications

The increased popularity of LEDs has challenged LED lighting technology to come up with efficient and cost effective solutions on the design of driver circuits. LED driver circuit uses buck, boost and buck-boost converters as switching power a conversion circuit which acts as a constant current source for LED lamps. These converters process a large amount of power during current regulation and hence they are inefficient. In this paper, we propose a highly efficient driver circuit with a fly-back converter as current regulator. The fly-back converter is placed between the dc source and the LED lamp. It uses only a partial power for current regulation and hence the efficiency is improved. Simulation results of open loop highly efficient LED driver with fly-back converter as current regulator is presented in this paper.

Ahire Akanksha Sunil

Papers

Analysis and simulation of a single stage power supply for LED lighting